1. Field of the Invention
The present invention relates to a folding device for web-fed rotary printing presses, that is, for the making of a longitudinal fold in the conveyed direction of the printed copies, the longitudinal fold being preferably produced after a cylinder cross-fold, the folding device including a folding blade disposed parallel to the conveying direction, the folding blade being suspended on two drive cranks, rotating at identical speed, and with the folding blade being moved up and down by drive cranks and, when in its bottom position, pushing the printed copies between two driven folding rollers.
2. Background of the Invention
In a known device (for example, in the device disclosed in German Patent No. 30 46 051), the folding blade is moved vertically in each direction during the folding operation through the intermediary of a planetary-gear system. In such a known device, the gear system requires lubrication (e.g., with oil), with the result that the possibility of lubricant getting onto the folded copies cannot be eliminated.